The influence of climate, soil, and management on the composition of native grass pastures on the central, southern, and Monaro tablelands of New South Wales

Pastures on 126 properties on the central, southern, and Monaro tablelands were surveyed to determine their botanical composition. Data on climate, so ils, pasture sowing, fertiliser history, and stock management were collecte d to relate current composition to environmental factors and previous manag ement. Native grass-based pastures were found to be widespread, and in many cases, pastures were dominated by native grasses, despite many decades of pasture improvement. Seventeen genera of native perennial grasses comprisin g over 35 species were identified. The most common species on the central t ablelands were Austrodanthonia spp., Bothriochloa macra, and Microlaena sti poides; on the southern tablelands, Austrodanthonia spp. and M. stipoides; and on the Monaro, Poa spp., Austrodanthonia spp., Themeda australis, and A ustrostipa spp. Soil type was the most important factor affecting species d istribution, and other soil attributes such as texture, pH, P, and N were a lso important. Environmental (rainfall) and management (superphosphate appl ication, stock type, stocking rate) factors also influenced distribution. T he significant areas of native grass pastures that were found suggest a dec line in sown species and a recolonisation of sown pastures with native gras ses. The potential for manipulation of botanical composition of these grass lands is discussed, together with their value for production and sustainabi lity.